Condeep
Troll A – The original concrete gravity‑based structure
Troll A is a monumental offshore natural gas platform in the North Sea and the original Condeep gravity‑based structure. This landmark achievement in offshore engineering is testament to the durability and reliability of concrete GBS.
This seabed‑founded approach, first proven at scale on Troll A, remains highly relevant for today’s offshore developments where simplified installation and reduced seabed intervention are critical.
Condeep is born - Breaking records on Troll A
- Location: North Sea, offshore Norway
- Project period: 1991–1996
- Client / Operator: Statoil (now Equinor)
- Structure type: Concrete gravity-based structure (Condeep)
Troll A is one of the most iconic offshore platforms ever built. The Condeep solution addressed several extreme engineering challenges associated with the Troll field. The concrete GBS enabled safe operation in deep water and harsh North Sea conditions while supporting extremely large gas volumes. By relying on its own weight, the structure stands directly on the seabed, eliminating the need for long steel piles or anchoring systems.
- Total height: 472 m (over 300 m submerged)
- Concrete volume: 245,000 m³
- Reinforcing steel: 100,000 tonnes
- Weight (unballasted): 683,600 tonnes
- Weight (operational): >1.2 million tonnes
- Original Condeep design setting the benchmark for offshore GBS platforms.
- Demonstrates unmatched scale, robustness and durability of concrete structures.
- Proven long-term performance in harsh North Sea conditions.